The present invention relates to thermographic diagnostic devices and methods in particular a device and method which detects localized areas on the skin exhibiting temperatures higher than the surrounding area and places a visual indication on the body corresponding to this localized area.
With the life expectancy in advanced countries increasing because of the virtual elimination of infectious disease as a major cause of death, death is mainly caused later in life by arterial diseases and cancer. Although some causes of cancer are known and a few remedies are effective, in many cases the only remedy available is early detection of the cancer followed by surgery, radiation therapy, chemotherapy or a combination of these. The most important factor in successful treatment appears to be early detection of the cancer before it becomes too massive and widespread to be countered.
Breast cancer has become the major cause of death in women aged 35 to 54. Early detection is of primary importance in breast cancer, as the extent of surgery depends on how much the cancer has spread. If detected early enough, simple surgery may be sufficient, but late detection may result in death or require radical and sometimes disfiguring surgery.
The major methods of detection of breat cancer used today are clinical examination by the physician, X-rays (mammography and xero-radiography) and Thermography. In clinical examinations, the breast is examined manually for lumps. If a lump is detected a biopsy is required to determined if the lump is malignant or benign. The cost of this method relative to the others is low, but the accuracy is also low.
In the mammography method, an X-ray examination of the breast is made from different angles and the presence of opacities is indicative of lesions. A positive mammogram is usually followed by a biopsy. The relative cost of this method is high, and the accuracy is high, but repeated examinations cannot be made because of the radiation hazard inherent in X-rays.
It is an object of this invention to provide a novel thermographic method and system for detecting breast cancer and other pathological conditions, which method and system is noninvasive and thus causes no damage to the body and can be repeated as many times as desired without harmful affects.
Thermography is based on the observation that malignant tumors and some other pathological conditions (e.g. arthritic joints, etc.) reveal their presence by localized hot areas of the skin in the vicinity of the tumor or abnormality. Thermographic equipment currently in use are highly sophisticated infrared scanning systems which produce a thermal image of the part of the body being examined. The thermal image is displayed on a cathode-ray tube screen and can be photographed for a permanent record. Examples of these systems are shown in U.S. Pat. Nos. 3,531,642 and 3,430,045.
U.S. Pat. No. 3,335,716 is an example of another method in which the body is coated with a phosphor that is excited to luminescence with ultraviolet radiation and a thermal pattern is displayed on a television tube. The relative accuracy of infrared or ultra-violet thermography for diagnosis of breast cancer is comparable to that of mammography. But, the image produced may not be accurate if heat sources or air currents in the room alter the thermal pattern produced on the surface of the body. Thus, elaborate chambers, free of drafts, heat producing lighting, and the like may be required for accurate work using infrared techniques.
It is accordingly an object of this invention to provide a novel thermographic detecting method and system which is relatively more accurate and inexpensive compared to the foregoing methods and systems.
It is another object of this invention to provide a novel method and system that detects and records localized hot areas of the skin without the inaccuracy of the infra-red method caused by air drafts and other ambient conditions.
Another system for detecting temperature variations on the skin involves the use of a temperature sensitive probe placed in contact with the skin. Examples of such systems are shown in U.S. Pat. Nos. 3,306,282, 3,751,694, 3,933,149, and 3,980,073. Direct contact of a temperature probe to the skin avoids the difficulties caused by air currents and skin surface evaporation in infra-red systems. But all direct contact prior art systems directed specifically to thermography require a special means for recording the measured temperature patterns, and further complications and possibilities for inaccuracies are typically introduced by such devices.
It is a further object of this invention to provide a novel thermographic diagnosing method and system which eliminates the recording inaccuracies and complications in prior art direct contact thermographic systems.
It is a more specific object of this invention to provide a novel method and system for detecting temperature variations on the skin which includes a probe containing a temperature responsive sensing element on one end of the probe for contact with the skin, and a marking device for placing a visual indication directly on the skin itself in the vicinity of the sensing element when a localized hot area has been detected.
In accordance with the present invention, abnormal conditions in the human body that are manifested by areas exhibiting skin temperatures above a predetermined value in relation to surrounding areas of the body (e.g. cancer), are detected and their locations are accurately recorded. A temperature responsive sensing element disposed for contact with the skin surface of an area of the human body provides a signal related to skin temperature at the location of contact. A marking means actuable between a marking and non marking condition selectively places a visual indication on the body in the vicinity of the sensing element when actuated in response to the temperature related signal exceeding a preselected value. In the preferred embodiment of this invention the marking means is a pen or other marking instrument contained in a hand held probe adjacent to the temperature sensing element. The pen is movable between an extended marking position and a retracted non-marking position. The pen is placed in the marking position when the temperature signal generated by the sensing element exceeds a preselected reference signal.
The present invention also relates to a method for diagnosing abnormal conditions in the human body that are manifested by an area exhibiting skin temperatures above a predetermined value in relation to surrounding areas of the body.The steps of the method include contacting a first location of a selected area of the body with a temperature responsive sensing element which generates a signal related to the temperature at that first location, moving the sensing element across the selected area along a desired path, comparing a reference signal with the signal produced by the sensing element as it is moved along the desired path, and marking locations on the body when the comparison indicates that a predetermined temperature differential has been exceeded.
The foregoing and other objects and advantages of the present invention will become apparent to one skilled in the art to which the invention pertains from the following detailed description when read in conjunction with the appended drawings.